| 摘要 |
PROBLEM TO BE SOLVED: To enable IF repeating of an FM signal between different radio bands. SOLUTION: An RF signal of the VHF band is converted by a frequency converter 103 to an IF signal of 10.7 MHz in frequency with a±37.5 kHz frequency shift quantity and this IF signal has its frequency converted by a frequency converter 107 after being multiplied by 4 through a 4-multiplier 105 to obtain an IF signal of 21.4 MHz in frequency with a±150 kHz frequency shift quantity. Then this IF signal is converted through frequency conversion 109 to an RF signal of the SHF band, so that the signal can be repeated as the frequency signals having the necessary frequency shift quantities for both the VHF and SHF bands. |
